I think it's usable, but it doesn't remember login name and passwords, so that affects it's usability the most. It's seriously primitive, but it is usable to some extent. It won't play any videos or audio. My favorite use for it is this:
Starfield Simulation - Fun Tesla Screen I don't think you can call that worthless, can you? LOL, the graphics look way better viewing this on my ten year old PC, than they do on my one year old Tesla's center screen. Oh well, luckily not being able to order my car from it wasn't a deal breaker.